IIBEC GCK And Registered Roof Consultant (RRC) Roofing Standards, Wind, And ASTM Fundamentals Practice Test

Scuppers provide a secondary drainage path for roof water and give a visible discharge at the roof edge. They are openings in parapets or edge walls that drain excess or overflow water directly to the exterior, which is why you see water flowing out onto the façade or beyond the roof edge. This makes them an overflow safety feature that works when primary drainage (like internal roof drains) is overwhelmed or blocked, helping to prevent ponding on the roof perimeter. Downspouts and gutters are part of the eaves drainage system—gutters collect water along the edge and feed it to downspouts that carry it away to the ground—so their discharge isn’t the visible edge-emptied flow you’d expect from a secondary roof-edge drainage. Vents are for ventilation of the roof assembly, not for removing water.